Registering articles to sites with recessed ultrasonic bonding tool head

Abstract

A head (158) precisely registers an article (10) to a site for operations such as bonding. The article (10) may be an electronic chip (10) containing a plurality of sides (12-15) having top edges for engaging the head (158) and bottom edges for registering to a topside (95) of a pedestal (20). A body (161) has an upper portion adapted for support and a lower portion terminating in a downwardly presented, working face (159). Face 159 includes a cavity (166) formed by walls (167-170) having inwardly and upwardly directed surfaces (171-174) for engaging corresponding top edges of the chip (10). The chip (10) is at least partially disposed within the cavity (166) making it difficult for an operator to see, especially when a fixed microscope is required for viewing. A bore (175) communicates with the cavity (166) and may be connected to a vacuum source for drawing a chip (10) into the cavity and for removably engaging the same to the engaging surfaces (171-174). Preferably, the front wall (168), facing the operator, has recessed end portions (100 and 102). Such recesses (100 and 102) reveal, preferbly extending to corners, bottom edges of the engaged chip (10) sufficient for registering such edges and the chip (10) to the topside (95) of the pedestal (20).

What is claimed is: 
     
       1. A head for registering an article to a site, said article containing a plurality of sides having top edges for engaging the head and bottom edges for registering to the site, comprising: a body having an upper portion adapted for support a plurality of exterior surfaces and a lower portion terminating in a downwardly presented, working face;   in said face, a cavity formed by a plurality of walls having inwardly and upwardly directed interior surfaces for engaging corresponding top edges of the article such that said article is at least partially disposed within said cavity;   means in said cavity adapted for removably engaging said article to said engaging surfaces; and   at least one of said walls having a portion at least equal to half of said wall but less than eighty percent of said wall which is sufficiently recessed such that a prism shaped channel extends from said exterior surface to said interior surface of said cavity to reveal bottom edges of an engaged article for registering such edges and the article to a site.   
     
     
       2. A head as in claim 1 wherein said body is supported in such a position that an article engaged to surfaces in the cavity is at least partially hidden from a viewing field of an operator by a front wall facing the operator, at the cavity, further comprising: said front wall having at least one end portion recessed sufficiently with respect to said viewing field to reveal to said operator, bottom edges of said article extending to at least one corner of the article for registering the article to a site.   
     
     
       3. A head as in claim 2 wherein the cavity is formed at least by the front wall and a back, substantially parallel, opposing wall for engaging an article therebetween, further comprising: said front wall having two end portions recessed and an intermediate portion remaining of sufficient strength to withstand forces transferred thereto by vibrating the engaged article sufficiently against a site to bond the article to the site.   
     
     
       4. Bonding apparatus having improved registration of an article to a site, said article having substantially flat upper and lower surfaces and a plurality of sides forming top edges for engaging the apparatus and, extending to respective corners of the article, bottom edges for registering to the site, comprising: a body having an upper portion adapted for support, a plurality of exterior surfaces and a lower portion terminating in a downwardly presented working face;   in said face, a cavity formed by a plurality of walls having inwardly and upwardly directed interior surfaces for engaging a corresponding plurality of top edges of the article sufficiently to hold said article in a desired position at least partially within said cavity;   means for communicating with said cavity for removably engaging said article to said engaging surfaces; and   at least one recess formed in a wall, said recess forms a prism shaped channel that extends from said exterior surface to said interior surfaces of said cavity, said recess being equal to at least half to said wall but less than eighty percent of said wall, sufficient to reveal bottom edges of an engaged article, said revealed edges extending to at least one corner of the article for registering the article to the site.   
     
     
       5. Apparatus as in claim 4, further comprising: means for supporting said body such that an article engaged to surfaces in the cavity is at least partially hidden from a viewing field of an operator by a front wall of the cavity facing the operator, further comprising:   said front wall having at least one end portion recessed sufficiently with respect to said viewing field to reveal to said operator, bottom edges of said article extending to at least one corner of the article for registering the article to a site.   
     
     
       6. Apparatus as in claim 5 wherein the cavity is formed at least by the front wall and a back, substantially parallel, opposing wall for engaging an article therebetween, further comprising: a recess formed in each respective end portion of the front wall and an intermediate portion remaining of sufficient strength to withstand forces transferred thereto by vibrating the engaged article sufficiently against a site to bond the article to the site.   
     
     
       7. Apparatus as in claim 6 wherein the article is a solid state chip having four sides and, in its top surface, features which may be damaged by mechanical contact, further comprising: the cavity formed by a front, a back, and two side walls having inwardly and upwardly converging surfaces adapted for engaging respective upper edges of the four sides of the chip sufficiently to hold such chip with a desired orientation and with a lower portion of said chip protruding from the working face of the body; said means for engaging the chip further including:   a bore in the body adapted for communicating between said cavity and a vacuum source of sufficient strength to hold the chip against the engaging surfaces during a vibratory bonding operation; and   said recesses in said end portions of said front wall extending into said side walls of the cavity to reveal in said viewing field, sufficient bottom edges at the front and sides of the chip for registering said chip to a site.   
     
     
       8. Apparatus as in claim 7 wherein the bonding site is on a component held in a bonding fixture and wherein the means for supporting the body and the registering further comprise: a horizontally extending coupling member having a free end connected to the body and a fixed connected to a bonder for imparting ultrasonic vibrations to the member, the body and the chip; and   means for producing relative motion between the bonder and the fixture for comparing bottom edges at corners of the chip held in the body to the site on the component in the fixture for registering and bonding the chip to the site.   
     
     
       9. A method of registering an article to a site for bonding, said article having substantially flat upper and lower surfaces and a plurality of sides forming top edges for engaging the apparatus and, extending to respective corners of the article, bottom edges for registering to the site, comprising: supporting a body by connection of an upper portion of the body such that a lower portion terminates in a downwardly presented working face;   producing relative motion between said body and an article to align said article to a cavity formed in said face by a plurality of walls, said walls having inwardly and upwardly directed interior surfaces for engaging a corresponding plurlaity of top edges of the article sufficiently to hold said article in a desired position at least partially within said cavity and said walls having outwardly directed exterior surfaces which correspond to the exterior surfaces of said body;   removably engaging said aligned article utilizing means communicating with said cavity for engaging said article to said engaging surfaces; and   comparing with the site, bottom edges of the engaged article revealed by a recess formed in a portion of a wall of the cavity, said recess forms a prism shaped channel that extends from said exterior surface to said interior surface of said cavity, said recess being equal to least half of said wall but less than eighty percent of said wall, said revealed edges extending to at least one corner of the article for registering the article to the site.   
     
     
       10. A method as in claim 9, wherein the supporting and comparing steps further comprise: supporting said body such that an article engaged to surface in the cavity is at least partially hidden from a viewing field of an operator by a front wall of the cavity facing the operator, further comprising:   comparing the site with the article along at least one end portion of said front wall, said portion being recessed sufficiently with respect to said viewing field that there is revealed to said operator, bottom edges of said article extending at least to one corner of the article for registering the article to a site.   
     
     
       11. A method as in claim 10 wherein the cavity is formed at least by the front wall and a back, substantially parallel, opposing wall for engaging an article therebetween, the comparing step further comprising: comparing the article with the site at recesses formed in respective end portions of the front wall, an intermediate portion of said front wall remaining, said intermediate portion having sufficient strength to withstand forces transferred thereto by vibrating the engaged article sufficiently against a site to bond the article to the site,   
     
     
       12. A method as in claim 11 wherein the article is a solid state chip having four sides and, in its top surface, features which may be damaged by mechanical contact, the motion producing step, the removably engaging step and the comparing step further comprising: aligning said article to said cavity formed by a front, a back, and two side walls having inwardly and upwardly converging surfaces adapted for engaging respective upper edges of the four sides of the chip sufficiently to hold such chip with a desired orientation and with a lower portion of said chip protruding from the working face of the body;   applying to said cavity, through a bore in the body, vacuum of sufficient strength to hold the chip against the engaging surfaces during a vibratory bonding apparatus; and   comparing the article to the site at said recesses in said end portions of said front wall, said recesses being extended into said side walls of the cavity to reveal in said viewing field, sufficient bottom edges at the front and sides of the wafer to register said wafer to a site.   
     
     
       13. A method as in claim 12 wherein the site for bonding is on a component held in a fixture and wherein the step of supporting the body, the registering and the bonding further comprise: connecting the body to a free end of a coupling member having a fixed end connected to a bonder capable of developing vibrations with ultrasonic frequency;   producing relative motion between the bonder and the fixture for comparing bottom edges at corners of the chip held in the body, to the site on the component held in the fixture, until a desired registration is achieved; and   transmitting from the bonder, ultrasonic vibrations to the member, the body and the chip for bonding the chip to the site.